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'IMPROVEMENT IN BALANGED STEAM-ENGINE vALvLs.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, TnoMAs RODDA, ofthe city and county of St-.- Louis, and State of Missouri, have invented a new and' useful Improvement in Balanced Valves; and I do herebydeclarc that the following is a full and cle'ar description thereof, reference being had to the accompanying drawings and to the lettersoi' n reference marked thereon.

Figure 1 of the drawings is a top plan of the improved valve.

Figure 2 is a side elevation of it. f i

Figure 3 is a horizontal. section takenv on the line c w, in iig. 2.

Figure 4 is a vertical section taken on the line :u y, in iig. 1.

The nature oi' this invention consists in the arrangement of two seatsl in that class of valves known as throttle valves, and in lthe admission of steam at all times to an equal hearing, both above and below the ,valvo, and resting upon it, so that but little power need be expended to open or close the valve.

To enable those skilled in the artto make and'use my invention, I will proceed t'o describe its construction and operation. I

A is s; section of pipe, which encloses the valve B. The ilange A1, around the top end of the pipe, is per-v forated with holes, for the purpose of attaching an outside pipe (not shown) thereto. When the outer pipe is attached tothe section A, there will be an annular opening between the two into-"which the steam will pass from the ports A2.. Of course the above-described construction of the ports is not new, and it may be widely varied, but it is deemed suiiciently explanatory of this part-of the drawings. The valve B is fitted snugly into the cylindrical opening in the centre of the pipe A, but S0 it can easily be moved up -or down. The cross-head B, attached to the upper end of the va1ve,.is perforated with an orifice in its centre for the reception of the valverod that is to operate it. The manner of attaching the valve-stem or rod to it ,may be varied. The-valve has two seats, b and b1, as clearly Shown in fig. 4, and on these alone, and not on the cylindrical joint between the valve and pipe, is dependence to be placed fora tight joint. The valve should be ground down on to its seats b and b. The lower'end of the valve 1':2 stops short before it reaches the'bottou al, so as to permit the steam to` get below the valve and press up against its bottom end, b2, with almost as much force as it presses down on the upper end of it, the only di'erence in pressure on the two ends being afslight diifercnce in'area, and' consequently the valve will be nearly balanced, and it can very easily be opened or closed. As soon as the`valve is raised high enough to open they ports A2, the steam will flow through them into the cylindrical opening between the pipe A and its surrounding pipe, as before described.

Having described my inventionu I claim the construction of the valve with its cross-piece B1, with reference to the openings and construction of the pipe A, arranged as hereinset forth. v THOMAS RODDA.

Witnesses: i

M. RANDOLPH, CHAS. H. BoYLE. 

